1. Field of the Invention
This invention relates to a portable information record medium such as a prepaid card
2. Description of the Related Art
Nowadays, cashless purchase and sale has become widespread. Cash is being replaced by cards. Particularly, prepaid cards are finding growing use. Well-known examples of prepaid cards are one which permits cashless use of public telephones and another one which enables cashless purchases of railway tickets Most of these cards can magnetically record the current state of use, e g., the balance on the card. On the surface of such a card, a plurality of amounts of money are printed. As the amount of money used on the card increases, holes are punched at the positions corresponding to the amounts of money that have been reached, thereby showing the user roughly how much money is left. However, the user of the card is unable to know from the card a more exact state of its use at the moment.
Because of this, prepaid cards have been developed in which the current state of use can be printed on the surface of the card as visible information. Japanese Patent Disclosure No. 61-48176 discloses such cards wherein the balance on the card and the date of use are printed on the surface of the card. However, this type of card does not permit information once printed to be erased or rewritten. Moreover, since the surface area of a card is limited, the amount of printable information is limited. Therefore, use of these cards is limited.
A conceivable method of displaying visible information is to provide the card with a seven-segment liquid crystal display. In this case, however, a power source needs to be provided in the card. In addition, the kinds of information that can be displayed are limited.